1. Field of the Invention
The present invention relates to a compressor motor, and more particularly to a magnet fixed structure for a compressor motor that improves reliability and efficiency of a compressor motor and increases mass productivity thereof by applying magnet fixing rings or a molding member in order to fix magnets to a magnet paddle.
2. Discussion of the background
FIG. 1 illustrates a linear compressor, which includes a hermetic vessel 10 which forms a housing of the compressor. The linear compressor includes, in part, an outer lamination 20 and an inner lamination 30, a cylinder 35, a magnet paddle 40, a piston 50, and a flange 80.
The inner lamination 30 is fixed at an inner side of an inner wall of a circumferential portion of the flange 80, and the outer lamination 20 is fixed at an outer side of the inner wall of the circumferential portion of the flange 80, the outer lamination 20 is spaced a predetermined from the inner lamination 30.
The magnet paddle 40 to which a plurality of magnets (not shown) are fixed is disposed between the inner lamination 30 and the outer lamination 20. Here, in order to improve efficiency of the compressor motor, each of the magnets fixed to the magnet paddle 40 should be provided thicker than an empty space between the two laminations 20, 30.
A plurality of helical-plate springs 60 are fixed at an end portion of the flange 80, and the piston 50 which linearly reciprocates in the cylinder 35 is coupled with a center portion of an inner side of the springs 60.
The cylinder 35 may be made up of the flange 80 itself, or formed separate from the flange 80 and fixed in the flange 80. In this example according to a convention art, the cylinder 35 is formed of the flange 80 itself.
The magnet paddle 40 connected to the piston 50 as a single body also reciprocates between the inner and outer laminations 30 and 20, together with the piston 50 which makes a linear reciprocation in the cylinder 35. The, the magnets are fixed to a predetermined portion of an outer circumferential surface of the magnet paddle 40.
A valve assembly 65 is provided at one side of the cylinder 35 and each muffler 70 is disposed at both sides of the valve assembly 65.
Now, referring to FIGS. 2A and 2B, a first example of a conventional structure in which the magnets are fixed to the magnet paddle 40 will be described.
According to the first example of the conventional magnet fixed structure, magnets 90 are fixed to an outer circumferential surface of the magnet paddle 40 by an adhesive at regular intervals. A plurality of slits 40a are formed in the magnet paddle 40 in order to reduce eddy current loss.
In FIG. 2A, a reference numeral 20a is a coil which is disposed in the outer lamination 20 and a power source is applied thereto, and a numeral 55 is a connecting member which connects the piston 50 to the magnet paddle 40.
With reference to FIGS. 3A and 3B, a second example of the conventional structure in which the magnets are fixed to the magnet paddle 40 will be described.
As shown therein, a plurality of grooves 41 for fixing the magnets are formed at the magnet paddle 40, and a plurality of magnets 90 are fixed to the corresponding grooves 41 by an adhesive.
However, according to the two above-described examples of the conventional magnet fixed structure, heat generated by the high-speed operation of the motor deteriorates the adhesive strength of the magnets and the magnet paddle, thus the magnets 90 eventually seperate from the magnet paddle 40.
With reference to FIGS. 4A and 4B, a third example of the conventional structure in which the magnets are fixed to the magnet paddle 40 will be described.
First, a base ring 42 and an end ring 43 are provided, and insertion grooves 42a and 43b are formed at facing surfaces of the base ring 42 and the end ring 43 and a plurality of magnets 90 are inserted into the corresponding grooves 42a and 43b.
After the magnets 90 are inserted to each of the insertion grooves 42a, 43a, the base ring 42 and the end ring 43 which hold the magnets 90 are fixed by slender bolts 44.
A reference numeral 45 is a nut for screwing onto each of the bolts 44 to fix the magnets 90, and reference numerals 20, 30 and 20a are the outer lamination, the inner lamination, and the coil, respectively.
However, since the above magnet fixed structure using the bolts 44 requires a complicated assembling process and a wide empty space between the inner 20 and outer 20 laminations, mass productivity of the compressor motor is limited and efficiency of the compressor motor is deteriorated.